The observational absence of giant convection cells near the Sun’s outer surface is a long-standing conundrum for solar modelers. We herein propose an explanation. Rotation strongly influences the internal dynamics, leading to suppressed convective velocities, enhanced thermal-transport efficiency, and (most significantly) relatively smaller dominant length scales. We specifically predict a characteristic convection length scale of roughly 30-Mm throughout much of the convection zone, implying weak flow amplitudes at 100- to 200-Mm giant cells scales, representative of the total envelope depth. Our reasoning is such that Coriolis forces primarily balance pressure gradients (geostrophy). Background vortex stretching balances baroclinic torques. Both together balance nonlinear advection. Turbulent fluxes convey the excess part of the solar luminosity that radiative diffusion cannot. We show that these four relations determine estimates for the dominant length scales and dynamical amplitudes strictly in terms of known physical quantities. We predict that the dynamical Rossby number for convection is less than unity below the near-surface shear layer, indicating rotational constraint.

太阳外表面附近没有观测到巨大的对流电池是太阳建模者长期以来的难题。我们在此提出一个解释。旋转强烈影响内部动力学，导致抑制对流速度，提高热传输效率，以及（最重要的是）相对较小的主要长度尺度。我们特别预测整个对流区的大部分特征对流长度尺度约为 30 毫米，这意味着 100 到 200 毫米巨细胞尺度的弱流动幅度，代表了总包络深度。我们的推理是科里奥利力主要平衡压力梯度（地转）。背景涡旋拉伸平衡斜压扭矩。两者一起平衡非线性平流。湍流通量传递了辐射扩散不能传递的多余部分的太阳光度。我们表明，这四个关系严格根据已知物理量确定主要长度尺度和动态幅度的估计。我们预测对流的动态罗斯比数在近地表剪切层下方小于统一，表明旋转约束。